08.07.2020 23:57, Andy Shevchenko пишет: > > > On Wednesday, July 8, 2020, Dmitry Osipenko <digetx@xxxxxxxxx > <mailto:digetx@xxxxxxxxx>> wrote: > > The gpiochip_add_data() takes care of setting the of_node to the > parent's > device of_node, hence there is no need to do it manually in the driver's > code. This patch corrects the parent's device pointer and removes the > unnecessary setting of the of_node. > > > I gave a second look and I think my suggestion is wrong. Here is an > interesting propagation of the parent device node to its grand son, > leaving son’s one untouched. Original code has intentions to do that way. The [1] says that gpio_chip.parent should point at the "device providing the GPIOs". That's the pdev->dev.parent in the case of this driver. MAX77620 is an MFD PMIC device that has virtual sub-devices like GPIO controller, PINCTRL and RTC. The MFD is the parent device that provides the GPIOs [2]. [1] https://elixir.bootlin.com/linux/v5.8-rc3/source/include/linux/gpio/driver.h#L276 [2] https://elixir.bootlin.com/linux/v5.8-rc3/source/arch/arm64/boot/dts/nvidia/tegra210-p2180.dtsi#L48 I think the old code was wrong and this patch is correct, please correct me if I'm missing something. > Suggested-by: Andy Shevchenko <andy.shevchenko@xxxxxxxxx > <mailto:andy.shevchenko@xxxxxxxxx>> > Signed-off-by: Dmitry Osipenko <digetx@xxxxxxxxx > <mailto:digetx@xxxxxxxxx>> > --- > drivers/gpio/gpio-max77620.c | 5 +---- > 1 file changed, 1 insertion(+), 4 deletions(-) > > diff --git a/drivers/gpio/gpio-max77620.c b/drivers/gpio/gpio-max77620.c > index 7f7e8d4bf0d3..39d431da2dbc 100644 > --- a/drivers/gpio/gpio-max77620.c > +++ b/drivers/gpio/gpio-max77620.c > @@ -279,7 +279,7 @@ static int max77620_gpio_probe(struct > platform_device *pdev) > mgpio->dev = &pdev->dev; > > mgpio->gpio_chip.label = pdev->name; > - mgpio->gpio_chip.parent = &pdev->dev; > + mgpio->gpio_chip.parent = pdev->dev.parent; > mgpio->gpio_chip.direction_input = max77620_gpio_dir_input; > mgpio->gpio_chip.get = max77620_gpio_get; > mgpio->gpio_chip.direction_output = max77620_gpio_dir_output; > @@ -288,9 +288,6 @@ static int max77620_gpio_probe(struct > platform_device *pdev) > mgpio->gpio_chip.ngpio = MAX77620_GPIO_NR; > mgpio->gpio_chip.can_sleep = 1; > mgpio->gpio_chip.base = -1; > -#ifdef CONFIG_OF_GPIO > - mgpio->gpio_chip.of_node = pdev->dev.parent->of_node; > -#endif > > platform_set_drvdata(pdev, mgpio); > > -- > 2.26.0 > > > > -- > With Best Regards, > Andy Shevchenko > >
